export default {
  parseUrlParams: function(url_) {
    const url = decodeURI(url_);
    let query = {};
    if (url.indexOf("?") != -1) {
      let i = url.indexOf("?");
      const str = url.substr(i + 1);
      const pairs = str.split("&");
      for (let i = 0; i < pairs.length; i++) {
        const pair = pairs[i].split("=");
        query[pair[0]] = pair[1];
      }
    }
    return query; // 返回对象
  },
  /**
   * 对象转url参数
   * @param {*} data,对象
   * @param {*} isPrefix,是否自动加上"?"
   */
  queryParams: function(data = {}, isPrefix = true, arrayFormat = 'brackets') {
    let prefix = isPrefix ? '?' : ''
    let _result = []
    if (['indices', 'brackets', 'repeat', 'comma'].indexOf(arrayFormat) == -1) arrayFormat = 'brackets';
    for (let key in data) {
      let value = data[key]
      // 去掉为空的参数
      if (['', undefined, null].indexOf(value) >= 0) {
        continue;
      }
      // 如果值为数组，另行处理
      if (value.constructor === Array) {
        // e.g. {ids: [1, 2, 3]}
        switch (arrayFormat) {
          case 'indices':
            // 结果: ids[0]=1&ids[1]=2&ids[2]=3
            for (let i = 0; i < value.length; i++) {
              _result.push(key + '[' + i + ']=' + value[i])
            }
            break;
          case 'brackets':
            // 结果: ids[]=1&ids[]=2&ids[]=3
            value.forEach(_value => {
              _result.push(key + '[]=' + _value)
            })
            break;
          case 'repeat':
            // 结果: ids=1&ids=2&ids=3
            value.forEach(_value => {
              _result.push(key + '=' + _value)
            })
            break;
          case 'comma':
            // 结果: ids=1,2,3
            let commaStr = "";
            value.forEach(_value => {
              commaStr += (commaStr ? "," : "") + _value;
            })
            _result.push(key + '=' + commaStr)
            break;
          default:
            value.forEach(_value => {
              _result.push(key + '[]=' + _value)
            })
        }
      } else {
        _result.push(key + '=' + value)
      }
    }
    return _result.length ? prefix + _result.join('&') : ''
  }
}
